Assume everything you write or e-mail an expert will be discoverable. Even if you can somehow keep it from being discovered, you will probably spend your time and the client’s money to keep it confidential. With that in mind, before you send anything to an expert ask yourself whether you would have a problem with the other side seeing it. If so, think long and hard before sending it. Also, folks have become too casual in what they include in e-mails, and I’ve found this true with experts, particularly their staff. So try to avoid e-mailing experts and their offices whenever possible, sticking to phone calls and faxes when possible. And ask them not to e-mail you. Yes, it is less convenient, but it will help ensure that the experts don’t make errant comments that become part of their permanent file (which at some point will likely have to be produced to the other side).